Biotreatment Soil Blend – Engineered Bioswale Soil for Stormwater Management in Marin, Sonoma, Napa & Solano
 
Our Biotreatment Soil Blend, also known as Bioswale Mix, is a premium engineered soil media specifically formulated to support green infrastructure and meet stormwater treatment requirements. Trusted by landscapers, engineers, and municipalities across Marin, Sonoma, Napa, and Solano counties, this soil mix is ideal for bioretention basins, swales, rain gardens, and LEED-certified projects.
 
Made from a balanced blend of screened sand, organic compost and other natural materials, this mix ensures optimal permeability, drainage, and nutrient content to support native plantings while filtering pollutants from stormwater runoff. Whether you're working on a public works project in San Rafael, a rain garden in Sonoma, or a bioswale installation in downtown Napa, this soil is engineered to perform under California’s Bay Area conditions.
 
Key Features & Notes:
Sustainable Composition: Blended with washed-screened sand and high-organic compost for optimal infiltration and microbial activity.
Engineered for Performance: Meets most local municipal and Caltrans specs for low-impact development (LID) and green stormwater infrastructure.
Versatile Use: Ideal for bioswales, bioretention cells, planter boxes, and rain garden applications.
Consistent Texture: Screened and blended to maintain permeability and resist compaction over time.
Permeability Rate: Meets typical stormwater BMP specifications for bioretention (check local agency requirements)
Organic Matter Content: Optimized to support plant health without nutrient leaching
pH Range: Neutral to slightly acidic (varies slightly by batch)
Moisture Content: Fresh-blended for consistency; may vary by season
 
Coverage Per Cubic Yard:
~ 150 sq ft 2" depth
~ 75 sq ft 4" depth
~ 50 sq ft 6" depth
~ 35 sq ft 8" depth
 
Weight Per Cubic Yard ~ 1.01 tons
Ships via - Dump Truck
 
Get a Bulk Delivery Quote Today! 
Serving: San Rafael | Mill Valley | Sonoma | Santa Rosa | Napa | Calistoga | Vallejo | Vacaville and surrouding areas.
 
⚠️ Always confirm with your local stormwater or environmental agency (e.g. Napa RCD, Sonoma Water, or Marin Municipal Water District) to ensure compliance with local biotreatment soil specs.
 
 
Frequently Asked Questions – Biotreatment Soil Blend
Q: Is this soil mix approved for use in city or county bioretention projects?
A: Our Biotreatment Soil Blend is engineered to meet general stormwater BMP specs and has been used in numerous projects across Marin, Sonoma, Napa, and Solano Counties. However, we recommend submitting the included data sheet to your local municipality or public works agency for approval, as requirements may vary.
 
Q: Can I use this mix in residential landscaping projects like rain gardens?
A: Absolutely. This blend is perfect for residential bioswales, rain gardens, and other low-impact development (LID) applications where drainage and pollutant filtration are critical.
 
Q: Do you deliver this soil blend to my city?
A: Yes, we deliver bulk orders across most of the North Bay, including Santa Rosa, Petaluma, Napa, Vallejo, San Rafael, Novato, Fairfield, and Vacaville. Just enter your ZIP code at checkout to confirm availability.
 
Q: How much does one cubic yard cover?
A: One cubic yard typically covers about 100 square feet at 3 inches deep. For deeper installations like bioretention basins, use our Material Volume Calculator to estimate your project needs.
 
Q: Does this mix contain compost that could clog drains over time?
A: No — we use a screened, stable compost that meets stormwater quality standards. The blend is engineered for long-term infiltration and plant health without compromising system performance.
 
Q: Is there a minimum order for delivery?
A: Yes, we require a minimum of 5 cubic yards for delivery. Larger orders may qualify for volume discounts. Contact us for contractor pricing if you're ordering for a public or commercial project.